I have run into a problem recently after using my usb powered dj mixer with my mobile pa setup. The setup I have currently is:
2 x 12v SLA batteries connected in series > dc voltage booster > TDA7498e D Class amp
Running in to that I have my laptop running off it's own battery and a usb powered dj mixer with RCA cords into the amp.
I had this setup for around 4 hours and it was working fine but after switching everything off and coming back the next day the dj mixer is now making a loud humming noise. It hums when I plug it into my other amps running on AC power as well. I'm trying to figure out if I damaged the mixer with my setup or if it was unrelated.
Should I have grounded the mixer to the battery somehow or is that not necessary? Any help or advice would be appreciated before I go and attach another mixer to the amp.
Thanks in advance
2 x 12v SLA batteries connected in series > dc voltage booster > TDA7498e D Class amp
Running in to that I have my laptop running off it's own battery and a usb powered dj mixer with RCA cords into the amp.
I had this setup for around 4 hours and it was working fine but after switching everything off and coming back the next day the dj mixer is now making a loud humming noise. It hums when I plug it into my other amps running on AC power as well. I'm trying to figure out if I damaged the mixer with my setup or if it was unrelated.
Should I have grounded the mixer to the battery somehow or is that not necessary? Any help or advice would be appreciated before I go and attach another mixer to the amp.
Thanks in advance
Swap out some audio cables. Connect the mixer to a separate power supply. (Battery)
Perhaps a ground loop between the mixer and the laptop?
Perhaps a ground loop between the mixer and the laptop?
Are you powering the mixer from the laptop usb , if so check that the laptop usb is still working .
Hi Guys
Thanks for the suggestions so far. The dj mixer I'm using (Pioneer DDJ SB) can only be powered by USB and had been working fine with my other speaker setup until I plugged it into the TDA7498e class D amp. After using these together the mixer started making a high pitch squeeling noise even when plugged into different amplifiers.
I've went out and bought the newer version of the dj mixer (Pioneer DDJ SB3) to try again. Everything was working fine with the new mixer when plugged into my regular speaker setup. Once I've plugged it into the 7498e the same problem happened. The new mixer now makes a high pitch hum when plugged into any speaker setup so I'm pretty sure I've destroyed this one as well.
I still think I should have grounded the mixer somehow.. anyone have any idea how I'd go about that with this mixer?
Thanks for the suggestions so far. The dj mixer I'm using (Pioneer DDJ SB) can only be powered by USB and had been working fine with my other speaker setup until I plugged it into the TDA7498e class D amp. After using these together the mixer started making a high pitch squeeling noise even when plugged into different amplifiers.
I've went out and bought the newer version of the dj mixer (Pioneer DDJ SB3) to try again. Everything was working fine with the new mixer when plugged into my regular speaker setup. Once I've plugged it into the 7498e the same problem happened. The new mixer now makes a high pitch hum when plugged into any speaker setup so I'm pretty sure I've destroyed this one as well.
I still think I should have grounded the mixer somehow.. anyone have any idea how I'd go about that with this mixer?
Stop blowing up mixers and measure what's on the input of your amplifier. Volts DC, AC, etc.
Chris
Chris
And ...it's not a mixer, but a MIDI DJ controller that You have. Many of the knobs and buttons only send MIDI. Your computer mixes and streams it to the USB port and that goes to a dual channel sound card in the console. I believe they use the NJM4580 Chip easy to find, so it is a matter of replacing the output OP-AMPS if they are blown. Pioneer usually uses clamp diodes and resistors on the outputs, so it shouldn't have blown. By the way have You tried without laptop PSU ground connected ? (3 to 2 prong adapter).. and Yes it's the Amp that is toasted, blowing gear. If You want to go the safe way, You can try a 1000 Ohm resistor in series on the line cables. Assuming 50V /1000 ohm =50 mA should be safe.
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